The present invention relates to an IC socket for use in detachably mounting an IC (an integrated circuit) on a printed circuit board.
FIG. 1 shows a conventional IC socket of this kind, which is proposed in Japanese Utility Model Laid-Open Application No. 118449/89 (corresponding to U.S. patent application Ser. No. 301,098 filed on Jan. 25, 1989). As depicted in FIG. 1, the conventional IC socket is composed of an insulating cover 10 and a rectangular parallelepipedic insulating housing 20 which are separable from each other. The insulating cover 10 includes a square panel 12 having pin insertion holes 11 and two parallel leg portions 14, each having in its sides 14a pin guide grooves 13 which communicate with the pin insertion holes 11 of the panel 12. The insulating housing 20 has two parallel chambers 21 for receiving the leg portions 14 of the insulating cover 10. In the inner wall surface of each side wall 21a of each chamber 21 there are provided side by side at regular intervals contactor receiving recesses 21b which extend in the direction in which each leg portion 14 is inserted into the chamber 21, and contactors 30 disposed in the recesses 21b are arranged in two files.
Each contactor 30 has a pin contact portion 33 at one end near the open end portion of the chamber 21 and a terminal portion 36 at the other end, which projects out of the housing 20 through a slot 23 made in its bottom panel 21d as shown in FIG. 2 and is connected to a printed circuit board by a surface mounting method, though not shown. An IC 40 is mounted on the insulating cover 10 with terminal pins 41 of the IC inserted in the pin guide grooves 13 through the holes 11 of the cover, and the insulating cover 10 thus carrying the IC 40 is mounted on the insulating housing 20 with the leg portions 14 of the cover pressed into the chamber 21 of housing 20 so that the terminal pins 41 of the IC 40 are each held in contact with the corresponding contactor 30 at a required pressure.
In the conventional IC socket depicted in FIGS. 1 and 2 the terminal portion 36 of each contactor 30 has a lance 35 for preventing the contactor 30 from falling off the insulating housing 20. The slot 23 in the bottom panel 21d of the insulating housing 20 is formed a little larger than the thickness and the width of the terminal portion 36 having the lance 35 that the terminal portion 36 can pass through slot, and consequently, the contactor 30 disposed in the 21b has some play. Hence, if an external force is applied as by a touch with the hand, the contactor 30 will tilt away from the bottom of the recess 21b, and when the insulating cover 10 is mounted on the insulating housing 20, the tip of the leg portion 14 of the insulating cover 10 or the terminal pin 41 of the IC 40 will collide with the protruding tip of the contactor 30. In this instance, if the insulating cover 10 is mounted on the insulating housing 20 by force, then the contactor 30 will likely be buckled. In addition, the contact portion 33 of the contactor 30 is spaced apart from the inner wall surface of the side wall 21a of the chamber 21 so that the contact portion 30 may be elastically urged against the inner wall surface by the terminal pin 41 of the IC 40. Hence when the terminal pin 41 is bent, there is a risk that it will enter housing or between the contactor 30 and the inner wall of the chamber 21 and is buckled.